A new thread to discuss DIY guitar pickups.
I recently built one using six electret microphones. Every other one is wired out of phase with the adjacent mic. The set of six therefore cancel, for far field sounds. Each is arranged to be below the corresponding string, which is near field to the mic. It works pretty well - I've had it out on stage at an open mic more than half a dozen times. Other players say it sounds good. Different sound than you'd get from a piezo bridge pickup or stick-on puck.
Why microphones? I normally play classical nylon, which of course doesnt work with the magnet based embodiment shown below. I melted the hot glue and ripped out the coil, to use the plastic shell as a pre-made holder for the electret mics to start. The three low strings on this guitar are from a nylon set.
I recently built one using six electret microphones. Every other one is wired out of phase with the adjacent mic. The set of six therefore cancel, for far field sounds. Each is arranged to be below the corresponding string, which is near field to the mic. It works pretty well - I've had it out on stage at an open mic more than half a dozen times. Other players say it sounds good. Different sound than you'd get from a piezo bridge pickup or stick-on puck.
Why microphones? I normally play classical nylon, which of course doesnt work with the magnet based embodiment shown below. I melted the hot glue and ripped out the coil, to use the plastic shell as a pre-made holder for the electret mics to start. The three low strings on this guitar are from a nylon set.
instead of dangling the pickup wire out like that, they make unobtrusive end-pin strap jacks more or less like: https://www.amazon.com/dp/B0CCS33T5...=d2lkZ2V0TmFtZT1zcF9kZXRhaWxfdGhlbWF0aWM&th=1 ...or else maybe: https://www.amazon.com/dp/B06Y2ZTMV...p_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWxfdGhlbWF0aWM
Other thing is that those look like they might be omni mics, in which case there is likely some phasing effect that may thin out and or comb filter the sound of each string.
Other thing is that those look like they might be omni mics, in which case there is likely some phasing effect that may thin out and or comb filter the sound of each string.
Thanks! The guitar actually has an endpin jack in it, which is connected to a Dayton exciter affixed to the back of the soundboard. It's due for a string change and I have a set of Martin "silk 'n steel" I want to put on; never tried them before. I was going to take that opportunity to reach in there, remove the exciter connection and wire up the pickup, which takes 3 conductors; + (1,3,5 mics), - (2,4,6 mics) and ground.
There's still the matter of a box with a small transformer and battery in it; can that dangle off the endpin jack via a TRS mounted to the box side? I can use a short cable; the box now hangs from the strap just above the endpin via another hole and strap pin mounted to it.
If I go for putting the battery (a 4.2V LiPo from a toy quadcopter) and the rest of the circuit inside, I might as well use the two pre-amp / compressor boards I bought to drive the 10k:10k center tapped mixing tranny, which means modifying each for a resistor change to source 3 electret mics I've wired in parallel, versus 1 it was designed for. I dont have any SMD parts on hand...
If the Martin "silk" strings are anything like classical nylons, they take a couple days to settle and stay in tune. Open mic is Friday, which gives me a day to get everything inside the guitar and hope it works as expected. I'll be lucky to get the cable inside and wired up, modify the box with the TRS plug / cable, leaving the circuit as is. I like to play 3 different songs every time I go, so I typically pick 3 and get familiar with them during the week for Friday. Not done. A colleague from Intel texted me they're having a lunch with several others on Thursday, which I missed last time...
Probably my best bet is to at least get the cable inside when I change the strings. The rest I can leave externally housed while working to get it upgraded; then when that's working as I hope, make a plan to get all of it mounted inside the guitar.
Interesting! How did you wire the capsules? The phase inverted ones will have the case terminal as "hot" which may give hum Problems. As there is already a battery you may think of some active op-amp electronics, trimpots for each string etc.
I used a small audio tranny, 10k:10K center tapped, to do the phase inversion. The 1,3,5 mics are wired to one primary winding end, the battery to the center tap (with current limiting resistor) and the 2,4,6 mics are wired to the other. Secondary winding provides the output, ground connects one side of the secondary, battery (-) and (-) of all six mics. It's relatively weak gain wise, but usable.
I bought a couple boards with actual electret mic preamps and compressor chips to hopefully bring up the gain to ordinary buffered pickup levels, but havent got a chance to implement them yet.
Anyone use one of these? I have two in hand. Bet you could get it to work with a dynamic mic as well - just accommodate the electret bias current, cap decouple to the Vcc/2 signal midpoint. Specs on the IC parts seem impressive for the $10 decade of expenditure. Ok, it's not a $35k Fairchild 660, but maybe with some I/O transformers? One would think you could build it right into the mic and have a vocal mic that "just does it".
My favourite (acoustic) is a cheap dual element piezoelectric sensor with the large and small sized elements used for bass and treble respectively. These may then be weighted and summed so as to obtain the desired tonal balance for the occasion.
I've never seen one arranged like that for guitar use. I think the smaller section was originally intended as feedback to make oscillation in the original application.
Yes, it is originally intended for an oscillator and being small, it picks up the treble separately without intermodulation with the bass, like 2-way. I've tried this on the violin (top plate) successfully and it should work on guitar as well. Needs some EQ to tame resonance.
Neat ...
For 20+ years the public school system in Florida offered night classes aimed at "Adult Education" in the same classrooms used to teach kids during the day. Many of these classes were aimed at the skills needed for life, like basic math, budgeting, reading and ESOL (English for Speakers of Other Languages). There were also classes in skills that could lead to employment, or hobby interests. For several years I attended a woodworking class. This class was divided into two groups, those of us who did not need much of the teacher's time, and the first timers who needed to learn the safe operation of all the serious equipment. This classroom was used for both woodworking and sheet metal work. A co-worker and I decided to make musical instruments. In a random stroke of luck both of us got to the point of (unamplified) first sound on the same night. This led to an impromptu jam session that went on until school security threw us out so that they could lock up the school for the night. It seemed that the only songs we both knew were old Beatles songs.
Sadly, school budget cuts killed all the fun classes. With only two classes left, I spent both of them making "rough cut" guitar bodies out of wood reclaimed from old waterbed frames with the band saw. Game over. I would leave Florida forever that same year as Motorola budget cuts killed my job. This was over 10 years ago.
I know that this creation is in this house somewhere and it had a "beat box" kind of button setup on the fat part above the neck. All I need to do if find it.
Sadly, school budget cuts killed all the fun classes. With only two classes left, I spent both of them making "rough cut" guitar bodies out of wood reclaimed from old waterbed frames with the band saw. Game over. I would leave Florida forever that same year as Motorola budget cuts killed my job. This was over 10 years ago.
I know that this creation is in this house somewhere and it had a "beat box" kind of button setup on the fat part above the neck. All I need to do if find it.
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Finding that picture last night woke up a few sleeping memory cells. The guitar had a neck with black tuners and a white nut. That neck has been sitting up on a shelf with strings and a Tele bridge pickup assembly hanging off of it for years. It's been sleeping with some of those ugly guitar bodies I made from waterbed frame wood. This told me that the guitar had been disassembled. I needed to look in some unlabeled moving totes that were on the same shelf. I hit the guitar and pickup parts jackpot in the first two totes. The important crate WAS labeled, on the other end. The rest were full of Sherri's craft stuff. The other half of the oddball guitar was in the unlabeled crate along with two more usable guitar bodies. The guitar with the speaker in it was inspired by a memory from my early years. There was a Lafayette Radio Electronics store next door to the slot car track where I raced my miniature electric car creations. The manager would let me sit near the door and play one of the guitars in the window. They had a guitar with a low powered transistor amp and speaker in it, which had a real neat "tone" for about half an hour as the batteries were dying.
It looks like I have several pickups, some parts and other goodies to play with including a complete Graphtech piezo bridge kit for a Strat. I have not found the box with dissected transducers in it, or the button assembly for the guitar. The button assembly came from Livid Electronics, which unfortunately went out of business many years ago. For some odd reason their web site is still alive. The missing box contains a Brain, a Brain JR, and several builder boxes with button boards.
https://lividinstruments.com/products/builder/
It looks like I have several pickups, some parts and other goodies to play with including a complete Graphtech piezo bridge kit for a Strat. I have not found the box with dissected transducers in it, or the button assembly for the guitar. The button assembly came from Livid Electronics, which unfortunately went out of business many years ago. For some odd reason their web site is still alive. The missing box contains a Brain, a Brain JR, and several builder boxes with button boards.
https://lividinstruments.com/products/builder/
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I like the unique shape in the 1st photo. Deserves to be finished off. From the video you posted in the other fellow's thread, it doesnt seem to matter all that much what the body is made from, nor it's shape, nor if there's even a body at all - you can still get a good electric guitar sound with decent pickups, solid hardware and whatever you put that's reasonable in the signal chain after.
There's a young guy at the open mic, great player and beginning to use a looper quite effectively. Influencing at least one other player, besides me. I asked him how long that loop was and he said a couple minutes! I bet he laid it down previously, then brought it to his set. He complained he didnt like the double tap to work it, wanted to contact the manufacturer and suggest a change. I see the "fat" head one's button row taking care of something like that. Or running a sequencer you can play against.
Nothing "wrong" with that. There's a guy that shows occasionally, calls himself The Shredder. He can too. He just brings some canned bass/drums thing he plays against, all pre-managed. That would be subject to criticism, but for his lead guitar playing, which I'd give my left --- to be able to do like he does. I spoke with him briefly and he said he's been playing the various modes as scales all his life. Ok...
A friend decades ago related his experience at a Jean-Luc Ponty show at Berklee. Started the show with a pre-programmed sequencer pattern. Audience reacted "Oh! Sequencer". Said Jean-Luc gave the audience a side eye, then proceeded to blow everyone away.
Us mortals do what we can with what we have. You "get up again, over and over".
There's a young guy at the open mic, great player and beginning to use a looper quite effectively. Influencing at least one other player, besides me. I asked him how long that loop was and he said a couple minutes! I bet he laid it down previously, then brought it to his set. He complained he didnt like the double tap to work it, wanted to contact the manufacturer and suggest a change. I see the "fat" head one's button row taking care of something like that. Or running a sequencer you can play against.
Nothing "wrong" with that. There's a guy that shows occasionally, calls himself The Shredder. He can too. He just brings some canned bass/drums thing he plays against, all pre-managed. That would be subject to criticism, but for his lead guitar playing, which I'd give my left --- to be able to do like he does. I spoke with him briefly and he said he's been playing the various modes as scales all his life. Ok...
A friend decades ago related his experience at a Jean-Luc Ponty show at Berklee. Started the show with a pre-programmed sequencer pattern. Audience reacted "Oh! Sequencer". Said Jean-Luc gave the audience a side eye, then proceeded to blow everyone away.
Us mortals do what we can with what we have. You "get up again, over and over".
The Martin "silk and phosphor" strings are a bit light, but they apparently dont have the issue of taking forever to become stable. I'm getting some over-drive on the mics, and it's amazing what they can take, right up to the string physically slapping against the mic head, which is of course excusable as a distortion source. Currently, I have to keep my strum way back by the bridge to prevent it, which is something I do anyway. I also need to use a thinner cork piece to lower the mic body some; havent yet thought of a way to make their hieghts individually adjustable. Still in "you get what you get" territory and even as such, the design is promising.
I read the Xenyx preamps in the Behringer mixer I use are actually pretty good, but only for the balanced input. I need to take advantage of that "every inch I can get" in signal dynamic handling, so the next mod will likely be going to an XLR cable from the I'll call it "mixer box", with the 10K:10K tranny in it, to the Behringer. That tranny enjoys driving the light TR instrument input now and in experimenting with load on it, seems to higher-pass with lower resistance load, apparently down to its 200Hz with 10K ratings.
I'm pretty sure I have plenty of signal there for an XLR mic level input, hopefully I can come up with a pad that both barely loads the tranny I have and provides enough differential signal to the little Behringer board I'm using as a "pedal". I can always just buy a proper tranny, but not by Friday!
I read the Xenyx preamps in the Behringer mixer I use are actually pretty good, but only for the balanced input. I need to take advantage of that "every inch I can get" in signal dynamic handling, so the next mod will likely be going to an XLR cable from the I'll call it "mixer box", with the 10K:10K tranny in it, to the Behringer. That tranny enjoys driving the light TR instrument input now and in experimenting with load on it, seems to higher-pass with lower resistance load, apparently down to its 200Hz with 10K ratings.
I'm pretty sure I have plenty of signal there for an XLR mic level input, hopefully I can come up with a pad that both barely loads the tranny I have and provides enough differential signal to the little Behringer board I'm using as a "pedal". I can always just buy a proper tranny, but not by Friday!
The body material can affect tone, but not much. It has a bigger affect on the sustain time and how loud the guitar will be when unplugged. Those old dried out waterbed frame bodies are quite loud. Poplar is nearly dead.
I had access to a wood shop for a few years via a night class at a Florida high school. I also collected a lot of scrap wood when the 70's - 80's waterbed fad had died off and the frames made of pine 2 X 10 boards were discarded. I made lots of odd shaped guitar bodies, slapped on a tailpiece and a Fender neck and tested the playability. I had been in the same 12 week long class through multiple repetitions with about 6 repeat offenders who knew me. Every 12 weeks we lost a bunch of people and gained some new ones. Those who knew me expected just about anything, but I surprized a batch of newbies when I seemingly constructed a guitar out of junk, put strings on it, played it for a few minutes, took the neck and strings off, and threw the body about 10 feet into the scrap wood bin.
Most of my successes were variations on that "X" shape.
Our church organized a road trip to a Christian music concert at a college over in Ohio about 5 years ago. For the most part the evening was quire enjoyable, but not overly exciting, until this old guy with 9 fingers named Phil Keagy got up and let loose on an acoustic guitar with multiple levels of looping. After that amazement subsided, he took out an ES-335 and blew everybody away.
I just grabbed this video at random. It does not show his real looping skill but check out the fret work around the 5 minute mark.
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Phil Keagy - I've heard the name. What a performer - wish I could move my hands like that! "Our age" too. That was impressive, singing into his guitar and looping it. Maybe hard to do with my out of phase microphones ;') Unless I can catch a side lobe or something.
There's modifications to these microphones that everyone knows about on line. I think they're - or can be - called the Linkwitz mod, after the famous speaker designer, who may have done it first to improve his DIY measurement microphone. It involves physically disconnecting the FET source from the case and using that as the output instead of or along with the drain, with the case still grounded. Supposed to allow the mic to give more dynamic range than the stock form circuit.
In my case, I'd need a bunch of these mics to operate on, as they say inevitably there will be some discards, as you have to successfully cut a trace on the back of the pretty small for my hands mic diameter. I realize they come in various sizes. The better Panasonic units of course arent made anymore. But I dont need measurement FR quality for what I'm doing with them; but any improved dynamic capability would be welcome, as with the preamp next in the signal chain.
For my preferences, all to compress it anyway, but having less clipping distortion upstream will be better. It's almost as fun to do a long sustain with a clean chord from an acoustic, as it is doing that via a dirty chord on an electric rig. Almost piano like, with a relatively constant amplitude while the harmonic balance changes over time type sound. Even a neophyte player like me can recognize when that's available and use it musically. Another fellow from the open mic uses compression on his Maton acoustic, with the sound hole plugged. I got to play his guitar and rig once and could "tell".
Here's an example of the mic mod and supporting circuitry to power from 48V phantom - It'll take a little rethinking to get the circuit below to power six mics simultaneously, with every other one 180 deg out of phase. Maybe not possible, due to max current limit of the 48V phantom spec, powering six mics instead of just one.
There's modifications to these microphones that everyone knows about on line. I think they're - or can be - called the Linkwitz mod, after the famous speaker designer, who may have done it first to improve his DIY measurement microphone. It involves physically disconnecting the FET source from the case and using that as the output instead of or along with the drain, with the case still grounded. Supposed to allow the mic to give more dynamic range than the stock form circuit.
In my case, I'd need a bunch of these mics to operate on, as they say inevitably there will be some discards, as you have to successfully cut a trace on the back of the pretty small for my hands mic diameter. I realize they come in various sizes. The better Panasonic units of course arent made anymore. But I dont need measurement FR quality for what I'm doing with them; but any improved dynamic capability would be welcome, as with the preamp next in the signal chain.
For my preferences, all to compress it anyway, but having less clipping distortion upstream will be better. It's almost as fun to do a long sustain with a clean chord from an acoustic, as it is doing that via a dirty chord on an electric rig. Almost piano like, with a relatively constant amplitude while the harmonic balance changes over time type sound. Even a neophyte player like me can recognize when that's available and use it musically. Another fellow from the open mic uses compression on his Maton acoustic, with the sound hole plugged. I got to play his guitar and rig once and could "tell".
Here's an example of the mic mod and supporting circuitry to power from 48V phantom - It'll take a little rethinking to get the circuit below to power six mics simultaneously, with every other one 180 deg out of phase. Maybe not possible, due to max current limit of the 48V phantom spec, powering six mics instead of just one.
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